Best known for playing Alo in the fifth and sixth series of E4 teen drama Skins, Merrick has also appeared on BBC One sitcom In with the Flynns and will feature in next year's Richard Curtis movie About Time.

Neil Gaiman has revealed that he wants to make the Cybermen "scary again" with his new episode, which will be directed by Stephen Woolfenden.

Doctor Who returns to BBC One this Christmas with festive special 'The Snowmen', with eight more regular episodes to follow in 2013.